Bert, Thank you for your reply (and the many other questions to the list that you answer).
I understand how order works when ordering based on a single column. What I don’t understand is how the code I included with my email works. I believe my problem is a lack of understanding of what with does. I have read about the with function, but I must be missing something. Thank you, John From: Bert Gunter <bgunter.4...@gmail.com> Sent: Monday, August 12, 2019 10:36 PM To: Sorkin, John <jsor...@som.umaryland.edu> Cc: r-help@r-project.org (r-help@r-project.org) <r-help@r-project.org> Subject: Re: [R] Trying to understand how to sort a DF on two columns https://stackoverflow.com/questions/2315601/understanding-the-order-function Do a web search on "How does order() work R" or similar for more. I can't explain with() any better than the docs: saying that it evaluates the expression argument in the data argument environment -- a data frame for the data frame method -- probably won't help you. -- Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Mon, Aug 12, 2019 at 7:20 PM Sorkin, John <jsor...@som.umaryland.edu<mailto:jsor...@som.umaryland.edu>> wrote: I want to sort a DF, temp, on two columns, patid and time. I have searched the internet and found code that I was able to modify to get my data sorted. Unfortunately I don't understand how the code works. I would appreciate it if someone could explain to me how the code works. Among other questions, despite reading, I don't understand how with() works, nor what it does in the current setting. code: data4xsort<-temp[ with( temp, order(temp[,"patid"], temp[,"time"])), ] Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org<mailto:R-help@r-project.org> mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
